Radical anti-government fighters in Syria mistakenly beheaded a wounded fellow rebel soldier after assuming he was a supporter of President Bashar al-Assad, according to an online statement from the radical fighters’ group.

A separate online video showed a gruesome display of radical fighters holding what appeared to be the victim’s head.

After the beheading earlier this week, the victim was determined to be Mohammed Fares, an anti-government fighter wounded in clashes against the Syrian Army earlier, according to the Syrian Observatory for Human Rights.

On Thursday, an online statement from a spokesman for the al Qaeda-affiliated Islamic State of Iraq and the Levant (ISIS), whose fighters apparently carried out the beheading of Fares, called for forgiveness for the killers and asked for “restraint and piety” from anti-government supporters.

In the separate online video, two fighters from ISIS are seen displaying what appears to be the decapitated head of a bearded man to a crowd in Syria’s commercial capital of Aleppo.

“He is an Iraqi Shiite volunteer fighter in Bashar al-Assad’s army,” a young man brandishing a knife in one hand and holding the decapitated head in another says in Arabic to a group of men all dressed in black.

“If they (al-Assad’s army) enter they will not distinguish between supporters and opponents. I swear they will rape the men before the woman,” another jihadi fighter continues in the amateur video.